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update error generic member access #243

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update error generic member access #243

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2bb600a
update build.rs probe to use error_generic_member_access
waynr Jul 28, 2023
68e3525
replace provide_any with error_generic_member_access
waynr Jul 28, 2023
e4a95dd
update build.rs probe to use error_generic_member_access
waynr Jul 28, 2023
1899bdd
update test_bactrace to use dyn Error for generic member access
waynr Jul 28, 2023
706570b
remove unnecessary ThiserrorProvide trait
waynr Jul 28, 2023
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35 changes: 26 additions & 9 deletions build.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,23 +4,40 @@ use std::path::Path;
use std::process::{Command, ExitStatus, Stdio};
use std::str;

// This code exercises the surface area that we expect of the Provider API. If
// the current toolchain is able to compile it, then thiserror is able to use
// providers for backtrace support.
// This code exercises the surface area that we expect of the Error trait's generic member access.
// If the current toolchain is able to compile it, then thiserror is able to offer backtrace
// support via generic member access.
const PROBE: &str = r#"
#![feature(provide_any)]
#![feature(error_generic_member_access)]

use std::any::{Demand, Provider};
use std::any::Request;

fn _f<'a, P: Provider>(p: &'a P, demand: &mut Demand<'a>) {
p.provide(demand);
#[derive(Debug)]
struct ErrorWithGenericMemberAccess {
it: u32,
}

impl std::fmt::Display for ErrorWithGenericMemberAccess {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "ErrorWithGenericMemberAccess")
}
}

impl std::error::Error for ErrorWithGenericMemberAccess {
fn provide<'a>(&'a self, request: &mut Request<'a>) {
request.provide_value::<u32>(self.it);
}
}

fn _get_u32(e: &dyn std::error::Error) -> Option<u32> {
e.request_value::<u32>()
}
"#;

fn main() {
match compile_probe() {
Some(status) if status.success() => println!("cargo:rustc-cfg=provide_any"),
_ => {}
Some(status) if status.success() => println!("cargo:rustc-cfg=error_generic_member_access"),
_ => {},
}
}

Expand Down
39 changes: 18 additions & 21 deletions impl/src/expand.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -60,52 +60,51 @@ fn impl_struct(input: Struct) -> TokenStream {
});

let provide_method = input.backtrace_field().map(|backtrace_field| {
let demand = quote!(demand);
let request = quote!(request);
let backtrace = &backtrace_field.member;
let body = if let Some(source_field) = input.source_field() {
let source = &source_field.member;
let source_provide = if type_is_option(source_field.ty) {
quote_spanned! {source.span()=>
if let std::option::Option::Some(source) = &self.#source {
source.thiserror_provide(#demand);
source.provide(#request);
}
}
} else {
quote_spanned! {source.span()=>
self.#source.thiserror_provide(#demand);
self.#source.provide(#request);
}
};
let self_provide = if source == backtrace {
None
} else if type_is_option(backtrace_field.ty) {
Some(quote! {
if let std::option::Option::Some(backtrace) = &self.#backtrace {
#demand.provide_ref::<std::backtrace::Backtrace>(backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(backtrace);
}
})
} else {
Some(quote! {
#demand.provide_ref::<std::backtrace::Backtrace>(&self.#backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(&self.#backtrace);
})
};
quote! {
use thiserror::__private::ThiserrorProvide;
#source_provide
#self_provide
}
} else if type_is_option(backtrace_field.ty) {
quote! {
if let std::option::Option::Some(backtrace) = &self.#backtrace {
#demand.provide_ref::<std::backtrace::Backtrace>(backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(backtrace);
}
}
} else {
quote! {
#demand.provide_ref::<std::backtrace::Backtrace>(&self.#backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(&self.#backtrace);
}
};
quote! {
fn provide<'_demand>(&'_demand self, #demand: &mut std::any::Demand<'_demand>) {
fn provide<'_request>(&'_request self, #request: &mut std::any::Request<'_request>) {
#body
}
}
Expand Down Expand Up @@ -246,7 +245,7 @@ fn impl_enum(input: Enum) -> TokenStream {
};

let provide_method = if input.has_backtrace() {
let demand = quote!(demand);
let request = quote!(request);
let arms = input.variants.iter().map(|variant| {
let ident = &variant.ident;
match (variant.backtrace_field(), variant.source_field()) {
Expand All @@ -259,23 +258,23 @@ fn impl_enum(input: Enum) -> TokenStream {
let source_provide = if type_is_option(source_field.ty) {
quote_spanned! {source.span()=>
if let std::option::Option::Some(source) = #varsource {
source.thiserror_provide(#demand);
source.provide(#request);
}
}
} else {
quote_spanned! {source.span()=>
#varsource.thiserror_provide(#demand);
#varsource.provide(#request);
}
};
let self_provide = if type_is_option(backtrace_field.ty) {
quote! {
if let std::option::Option::Some(backtrace) = backtrace {
#demand.provide_ref::<std::backtrace::Backtrace>(backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(backtrace);
}
}
} else {
quote! {
#demand.provide_ref::<std::backtrace::Backtrace>(backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(backtrace);
}
};
quote! {
Expand All @@ -284,7 +283,6 @@ fn impl_enum(input: Enum) -> TokenStream {
#source: #varsource,
..
} => {
use thiserror::__private::ThiserrorProvide;
#source_provide
#self_provide
}
Expand All @@ -298,17 +296,16 @@ fn impl_enum(input: Enum) -> TokenStream {
let source_provide = if type_is_option(source_field.ty) {
quote_spanned! {backtrace.span()=>
if let std::option::Option::Some(source) = #varsource {
source.thiserror_provide(#demand);
source.provide(#request);
}
}
} else {
quote_spanned! {backtrace.span()=>
#varsource.thiserror_provide(#demand);
#varsource.provide(#request);
}
};
quote! {
#ty::#ident {#backtrace: #varsource, ..} => {
use thiserror::__private::ThiserrorProvide;
#source_provide
}
}
Expand All @@ -318,12 +315,12 @@ fn impl_enum(input: Enum) -> TokenStream {
let body = if type_is_option(backtrace_field.ty) {
quote! {
if let std::option::Option::Some(backtrace) = backtrace {
#demand.provide_ref::<std::backtrace::Backtrace>(backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(backtrace);
}
}
} else {
quote! {
#demand.provide_ref::<std::backtrace::Backtrace>(backtrace);
#request.provide_ref::<std::backtrace::Backtrace>(backtrace);
}
};
quote! {
Expand All @@ -338,7 +335,7 @@ fn impl_enum(input: Enum) -> TokenStream {
}
});
Some(quote! {
fn provide<'_demand>(&'_demand self, #demand: &mut std::any::Demand<'_demand>) {
fn provide<'_request>(&'_request self, #request: &mut std::any::Request<'_request>) {
#[allow(deprecated)]
match self {
#(#arms)*
Expand Down
6 changes: 1 addition & 5 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -236,12 +236,10 @@
clippy::return_self_not_must_use,
clippy::wildcard_imports,
)]
#![cfg_attr(provide_any, feature(provide_any))]
#![cfg_attr(error_generic_member_access, feature(error_generic_member_access))]

mod aserror;
mod display;
#[cfg(provide_any)]
mod provide;

pub use thiserror_impl::*;

Expand All @@ -250,6 +248,4 @@ pub use thiserror_impl::*;
pub mod __private {
pub use crate::aserror::AsDynError;
pub use crate::display::{DisplayAsDisplay, PathAsDisplay};
#[cfg(provide_any)]
pub use crate::provide::ThiserrorProvide;
}
15 changes: 0 additions & 15 deletions src/provide.rs
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This file was deleted.

59 changes: 19 additions & 40 deletions tests/test_backtrace.rs
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
#![cfg_attr(
thiserror_nightly_testing,
feature(error_generic_member_access, provide_any)
feature(error_generic_member_access)
)]

use thiserror::Error;
Expand All @@ -19,7 +19,6 @@ pub struct InnerBacktrace {
#[cfg(thiserror_nightly_testing)]
pub mod structs {
use super::{Inner, InnerBacktrace};
use std::any;
use std::backtrace::Backtrace;
use std::error::Error;
use std::sync::Arc;
Expand Down Expand Up @@ -106,74 +105,54 @@ pub mod structs {
let error = PlainBacktrace {
backtrace: Backtrace::capture(),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = ExplicitBacktrace {
backtrace: Backtrace::capture(),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = OptBacktrace {
backtrace: Some(Backtrace::capture()),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = ArcBacktrace {
backtrace: Arc::new(Backtrace::capture()),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = BacktraceFrom::from(Inner);
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = CombinedBacktraceFrom::from(InnerBacktrace {
backtrace: Backtrace::capture(),
});
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = OptBacktraceFrom::from(Inner);
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = ArcBacktraceFrom::from(Inner);
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = AnyhowBacktrace {
source: anyhow::Error::msg("..."),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = BoxDynErrorBacktrace {
source: Box::new(PlainBacktrace {
backtrace: Backtrace::capture(),
}),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
}

// https://github.com/dtolnay/thiserror/issues/185 -- std::error::Error and
// std::any::Provide both have a method called 'provide', so directly
// calling it from generated code could be ambiguous.
#[test]
fn test_provide_name_collision() {
use std::any::Provider;

#[derive(Error, Debug)]
#[error("...")]
struct MyError {
#[source]
#[backtrace]
x: std::io::Error,
}

let _: dyn Error;
let _: dyn Provider;
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());
}
}

#[cfg(thiserror_nightly_testing)]
pub mod enums {
use super::{Inner, InnerBacktrace};
use std::any;
use std::backtrace::Backtrace;
use std::sync::Arc;
use thiserror::Error;
Expand Down Expand Up @@ -259,36 +238,36 @@ pub mod enums {
let error = PlainBacktrace::Test {
backtrace: Backtrace::capture(),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = ExplicitBacktrace::Test {
backtrace: Backtrace::capture(),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = OptBacktrace::Test {
backtrace: Some(Backtrace::capture()),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = ArcBacktrace::Test {
backtrace: Arc::new(Backtrace::capture()),
};
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = BacktraceFrom::from(Inner);
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = CombinedBacktraceFrom::from(InnerBacktrace {
backtrace: Backtrace::capture(),
});
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = OptBacktraceFrom::from(Inner);
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());

let error = ArcBacktraceFrom::from(Inner);
assert!(any::request_ref::<Backtrace>(&error).is_some());
assert!((&error as &dyn std::error::Error).request_ref::<Backtrace>().is_some());
}
}

Expand Down
2 changes: 1 addition & 1 deletion tests/test_option.rs
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
#![cfg_attr(
thiserror_nightly_testing,
feature(error_generic_member_access, provide_any)
feature(error_generic_member_access)
)]

#[cfg(thiserror_nightly_testing)]
Expand Down